Cushioning device for pistons.



No. 886,402. PATENTED MAY 5, 1908. O. S. PIKE.

GUSHIONING DEVICE FOR PISTONS.

APPLICATION IILED SEPT. 16, 1904.

UNITED err-ares aras OTTO S. PIKE, OF MALDEN, MASSACHUSETTS, ASSIGNOR TO AMERICAN PNEUMATIC SERVICE COMPANY, OF DOVER, DELAWARE, A'COBPORATION OF DELAWARE cusnroivme DEVICE-FOR rrs'rons.

Specification of Letters Patent.

Patented May 5, 1908.

Application filed September 16, 1904. Serial No. 224,643.

My invention relates to reciprocating pistons operated by fluid and itsobject isto provide means whereby the piston reciprocatmg in the cylinder can be brought to rest or reversed in its motionat the end of its stroke without shock or jar. k

My invention consists of certain novel features hereinafter described and particularly pointed outin the claims.

In the accompanying v drawings which illustrate a construction embodying my invention, Figure shows a section of the apparatus with the piston to the right of the cylinder. Fig. 2 shows a similar section with the piston at the left of the cylinder. Fig. 3 shows a section of the valve chest, on the line it wFig. 1. I

Like letters of reference refer to like parts throughout the several views.

A is the cylinder and A the piston; the piston A is operated by ,motive fluid from any suitable source through the .pi e A The admission of this motive fluid't rough the cylinderA is controlled-by the piston slide valve C in the valve, chest M. The construction of this valve 0 and valve chest Mis welfknown to the art. The motive fluid being admitted to the right or to; the left of the piston A according as 'the. valve C .is in its right hand or left hand osition in the valve chest M. Fig. 1 shows t s valve G in its left hand osition, and Fig. 2 shows the valve in its right Iiand position. This'valve C may be operated manually or byany suitable mec anical'means. In the cylinder heads F F are the check valves F F; these valves open inwardly and the springs. F" and F tend to hold themwin a closed position. When the piston A is stationary both valves F F? would be closed on their seats unless prevent? ed by the adjusting screws F. F hereinafter described. In Figfl however, the valve F is shown in the position it would take when the piston A is moving to the right, and in Fig. 2 the valve F is shown in the position it would .take when the piston A is moving to the left. -The purpose'of these valves F F is to secure an air cushion at the ends of the cylinder A to prevent the piston A from coming to the end of its stroke with a shock.

port D the valve chest M, the port M and pipe M into the atmosphere. As the piston A nears the end of its motion'toward the right, it overlaps the opening M of the port D and the pressure generated in the closed space combined with the spring F tends to keep the valve tightly closed. The valve 'F however, may be keptfrom-entirely closing by the adjusting screw F so that the motive fluid may esca e by the valve F slowly, and thus allow t e piston A to come home slowly.

In case the nature of the work of the apparatus does not necessitate the piston A ending its stroke at an exact point, the adjustin screw F" may be drawn back so that the right hand motion of the piston A; and consequently causing the piston A to come to rest on a cushion madeof the motive fluid instead of allowing the piston to strike the cylinder head M When the motive fluid is admitted to the ort D so as to force the iston A to the let, some of the motive uid can pass through the ort D to the right of the valve F and by orcing open the valve F can pass into the cylinder to the right of the piston A 'After the piston A- has moved a short distance to the left, the opening I of the port D is uncovered by the piston A thus allowing the full volume of motive fluid to enter the cylinder. The action of the valve F is entirely similar to that of the valve F previously described.

I do not limit myself to the arrangement and construction shown as the same may be varied without departing from the spirit of my invention. I

Having thus described the nature of my invention and set forth a construction embodying the same, what I claim as new and desire to secure by Letters Patent of the United States is: p

1. In an apparatus of the character described, a cylinder, a iston in said cylinder, a valve controlling t e admission and exhaust of the motive fluid to and from said c linder, a valve for cushioning the piston at t e end of its stroke, and means for adjusting said valve.

2 In an apparatus of the character described, a cylinder, a piston in said cylinder, I name to this specification in the presence of avalve controlling the admission andexhaust two subscribing Witnesses, this twelfth day of the motive fluid to and from said cylinder, of September A. D. 1904.

a valve at each end of the cylinder for cush- OTTO S. PIKE. 5 ioning the iston at the end of its strokes, 1 Witnesses:

and means or adjusting said valves. A. L. N USSIL,

In testimony whereof, I have signed my} E. L. HARLOW. 

